Last year, AdSense has partnered with MTV Networks, where Google distributed ad-supported MTV video content to publishers who displayed the content on their sites. Google plans to expand its testing to a larger range of publishers from small to large, and cut across many different types of content.
This time, we'll be working with a larger set of content providers, grouping together video content from providers such as Warner Music Group and Sony BMG Music Entertainment together with quality ads and offering them as playlists which publishers can select from and display on their AdSense sites.I have no idea what type of site Google is aiming at and the definition of small publishers (but of course, to get the best results from testing, they need a large sampling size which in this case means a site with high traffic volume). If you are being invited by AdSense, please share your experience with us!
Related: Inside AdSense - This is a test: Video content on AdSense